Pay per click (PPC) is an advertising model used on search engines, advertising networks, and content websites/blogs, where advertisers only pay when a user actually clicks on an ad to visit the advertiser's website. Advertisers bid on keywords they predict their target market will use as search terms when they are looking for a product or service. When a user types a keyword query matching the advertiser's keyword list, or views a page with relevant content, the advertiser's ad may be shown. These ads are called a "Sponsored link" or "sponsored ads" and appear next to or above the "natural" or organic results on search engine results pages or anywhere a webmaster/ blogger chooses on a content page.

Pay per click ads may also appear on content network websites. In this case, ad networks such as Google AdSense and Yahoo! Publisher Network attempt to provide ads that are relevant to the content of the page where they appear, and no search function is involved.

While many companies exist in this space, Google AdWords, Yahoo! Search Marketing, and Microsoft adCenter are the largest network operators as of 2007. Depending on the search engine, minimum prices per click start at US$0.01 (up to US$0.50), these prices are often referred to as Costs Per Click (CPC). Very popular search terms can cost much more on popular engines. Arguably this advertising model may be open to abuse through click fraud, although Google and other search engines have implemented automated systems to guard against this.

Pay per call

Similar to pay per click, pay per call is a business model for ad listings in search engines and directories that allows publishers to charge local advertisers on a per-call basis for each lead (call) they generate. The term "pay per call" is sometimes confused with "click to call. Click-to-call, along with call tracking, is a technology that enables the “pay-per-call” business model.

Pay-per-call is not just restricted to local advertisers. Many of the pay-per-call search engines allow advertisers with a national presence to create ads with local telephone numbers.

WAIRS PPC